ES2547313T3 - Rotary cutting tool that has an adjustable cooling mechanism and corresponding cooling method - Google Patents

Abstract

A cutting tool (10) comprising a cutting body (12) having a central body hole (32), a central pin (54) seated within the central body hole (32); wherein: the tool body (12) comprises: a front body face (14); a rear body face (16), opposite to the front body hull (14); one each peripheral body rear (18), which extends backwards from the front body face (14); and at least one channel (20) formed in the peripheral body face (18) and extending backwards from the front body face (14), the at least one channel comprising a first row of insert pockets adjacent to the front body face (14) and at least a second row of insert pockets axially displaced backwards with respect to the first thin one, where each of the insert pockets (22) is associated with a cooling hole (30) which is in fluid communication with the central body hole (32); and a cutting insert (24) retained within each of the insert pockets (22), the cutting inserts (24) being retained in the first row of insert pockets forming a first row (98) of cutting inserts , and the cutting inserts (24) being retained in the second row of insert pockets formed a second row (100) of cutting inserts; characterized in that a resealable seal (94) is seated in the central pin (54), where when the reclosable seal (94) is seated in a first sealing position along the central pin (54), the central hole of body (32) is in fluid communication with a first number of rows of cutting inserts; and when the removable seal (94) is seated in a second sealing position along the central pin (54), the central body hole (32) is in fluid communication with a second number of rows of cutting inserts that It is different from the first number of rows of cutting inserts.

Description

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DESCRIPTION

Rotary cutting tool that has an adjustable cooling mechanism and corresponding cooling method

FIELD OF THE INVENTION

This invention relates to a rotary cutting tool, such as a channel or groove cutter according to the preamble of claim 1, as is known from DE 10 2004 055 377A1, and to a cooling method for adjusting a mechanism of cooling according to the preamble of claim 11 as known from US 4,610,579A.

BACKGROUND OF THE INVENTION

Channel strawberries are well known in the industry. They are capable of using one or more sets of cutting inserts, each comprising several consecutive cutting inserts arranged on the periphery of the cutter, which axially overlap each other to form a long peripheral effective cutting edge for milling, for example, a deep shoulder whose depth is greater than the length of a lateral cutting edge of a single cutting insert. In the circumferential direction of the cutter, each cutting insert is considered to belong to a circumferential row ("row"), each row typically having at least as many cutting inserts as the number of assemblies.

As a result of a growing demand for high productivity cutting tools, many extended channel milling cutters available in the market are provided with internal cooling ducts in order to supply a cooling means to the cutting inserts. Some drills are provided with cooling holes adjacent to the cutting inserts mounted therein in order to efficiently supply a cooling means to the active cutting edge of each of the cutting inserts.

In some applications, for example, when a shallow shoulder whose depth is less than the length of the extended channel cutter, not all the arrows of the cutting inserts are used. For example, if the milling cutter is provided with five rows of cutting inserts, it may be that only the first two axially further forward are active while the three axially more rearward rows of the cutting inserts are unnecessarily cooled. As a result, the refrigerant flow rate was used inefficiently since it could have been directed entirely only to the active rows. This leads, of course, to unnecessary operating costs that could be saved.

One solution to this deficiency, as several tool manufacturers have suggested, is to produce the threaded cooling holes. Thus, if it is required not to use several rows of cutting inserts, the respective cutting holes are covered with screws that are threadedly coupled with the threads of the cooling holes.

Even if the consequence of such a solution is to cool only the active rows of the cutting inserts, this solution may not be practical since it may require threadedly coupling or uncoupling a large number of very small screws every time a change in depth is required. cutting, a task that takes a long time.

It is an object of the present invention to provide an extended channel mill that overcomes the aforementioned disadvantages.

It is a further object of the present invention to provide a quick and easy method to limit the number of rows of cutting inserts that receive the refrigerant through the internal cooling holes.

Document DE 10 2004 055 377 A1 discloses a cutting tool that has cooling / lubricating channels with different cross sections that are in fluid communication with a common supply of cooling / lubricating means. A distribution set is arranged to divide the flow of coolant / lubricant into at least two partial flows of defined flows.

In addition, US 4,610,579 discloses a mouth for a core drill of the type for drilling a beveled hole in an article having a dynamic flow that directs an element to cool the mouth and article surfaces during the drilling and beveling of the article. .

SUMMARY OF THE INVENTION

In accordance with the present invention a cutting tool is provided as defined in the features of claim 1.

Practically, the resealable seal is a ring.

In some embodiments, the central pin extends backward to a rear end of the central pin.

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Advantageously, the central grooved portion of the central pin comprises at least one pin cooling outlet that is in fluid communication with the central pin hole.

If desired, a leading end of the center pin hole is plugged with a plug

In some embodiments, the rear part of the central pin comprises a rear threaded part

Typically, a front part of the central pin comprises a screw head.

In some embodiments, the central pin comprises an axial pin-bearing surface backward toward the central grooved portion.

If desired, the cutting tool comprises an auxiliary seal seated within a slot of secondary seal groove in a hole that is turned forward of the central hole of the body.

Still in accordance with the present invention, a method is provided as defined by the features of claim 11.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding, the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Fig. 1 is a perspective view of a cutting tool according to the present invention;

Fig. 2 is a perspective view of a central pin with a reclosable seal mounted thereon;

Fig. 3 is an exploded view of the cutting tool;

Fig. 4 is a lateral cross section of the cutting tool;

Fig. 5 is a cross section of the cutting tool taken in a first position of the removable seal;

Fig. 6 is a cross section of the cutting tool taken in a second position of the removable seal; Y

Fig. 7 is a cross section of the cutting tool taken in a third position of the removable seal.

DETAILED DESCRIPTION OF THE INVENTION

Reference is made to Figs. 1 to 7, which show a cutting tool 10 in accordance with the present invention. The cutting tool 10 has a rotation axis A, which defines a direction from front to back, and comprises a cutting body 12 having a front cutting face 14, generally perpendicular to the axis of rotation A, to the rear face of the body 16, opposite the front face of body 14, and a peripheral body face 18 extending from the front face of body 14 to the rear face of body 16.

The tool body 12 is provided with a plurality of channels 20 formed in the peripheral face of body 18 and extending backwards from the front face of the body 14. The cutting tool 10 shown in the drawings is provided with five channels 20 It is to be understood, however, that the cutting tool 10 according to the present invention is not limited to having five channels 20 and any number of channels 20 may be applicable, for example, one, two, three, and so on.

Each channel 20 comprises a plurality of insert pockets 22 that are axially offset with respect to each other. It should be noted that the present invention is particularly applicable for channels 20 that have at least two insert pockets 22, but channels 20 that have a larger number of insert pockets 22 are similarly applicable.

A cutting insert 24 is retained in each of the insert pockets 22 by means of a retaining screw 26. Cutting tools of the type shown in the figures are often referred to in the art as extended channel drills since, as mentioned above, the cutting inserts are arranged in such a way that they axially overlap each other to form a long peripheral effective cutting edge with an axially associated associated channel. The construction of the insert pockets and the manner of forming the long peripheral effective cutting edge are not essential features of the present invention and therefore will not be described in detail. Generally speaking, however, cutting inserts in a given channel can be considered to form a "set" of cutting inserts.

A peripheral cutting edge of each of the cutting inserts 24 constitutes a peripheral cutting edge 28 if it participates in a machining process. A cooling hole 30 is associated with each of the inserts of

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cutting 24 in order to supply a cooling fluid directly to each of the active peripheral cutting edges 28. Each cooling hole 30 is in fluid communication with a central body hole 32, as best seen in Figs. 5, 6 and 7. According to a specific embodiment, as shown in the figures, the central body hole 32 extends from the front body face 14 to the rear body face 16 and comprises first 34, second 36, third 38 and fourth 40 hole parts having respectively first D1, second D2, third D3 and fourth D4, diameters.

The first hole part 34, which constitutes a front hole part, extends backward from the front body face 14. A rear part of the first hole part 34 constitutes a face of holes turned forward 42 which is substantially perpendicular to the axis of rotation A. The face of holes turned forward 42 comprises a secondary sealing groove in the shape of a ring 44 extending around the axis of rotation A.

the second hole part 36, which constitutes a central hole part having a central hole part wall 46, extends backward from the first hole part 34. The second diameter D2 of the second hole part 36 is more smaller than the first diameter D1 of the first hole part 34. The second hole part 36 is provided with internal cooling holes 48 that are in fluid communication with the cooling holes 30 through the cooling ducts 50. Typically, for greater ease of manufacture, the cooling ducts 50 extend in a straight line from the cooling hole 30 to its corresponding internal cooling hole 48. A rear end of the second part of holes 36 constitutes an axial bearing surface of turned holes forward 52. In one embodiment, the axial hole bearing surface 52 may be perpendicular to the axis d and rotation A. However, in other embodiments, the axial hole bearing surface may be inclined with respect to the axis of rotation A.

The third hole part 38, which constitutes an intermediate hole part, extends backward from the second hole part 36. The third diameter D3 of the third hole part 38 is smaller than the second diameter D2 of the second part. of hole 36.

The fourth hole part 40, which constitutes a rear hole part, extends backward from the third hole part 38. The fourth diameter D4 of the fourth hole part 40 is larger than the third diameter D3 of the third part. of hole 38.

A central pin 54 is seated within the central body hole 32. The central pin 54 is generally symmetrical with respect to a pin axis B and comprises a front cover part 56, a central grooved part 58 extending rearwardly from the front stage part 56, and, a rear threaded portion 60 extending rearwardly from the central grooved portion 58. A pin hole 62 extends through the central pin 54 along the entire length thereof.

The front cover portion 56 has a first diameter D5, which constitutes a cover diameter. The fifth diameter D5 is larger than the second diameter D2 and smaller than the first diameter D1. The front cover portion 56 has a front cover surface 64, an opposite rear cover surface 66, and a peripheral cover surface 68 therebetween.

The central pin hole 62 opens to the front cover surface 64 and can be plugged by a plug

70. The plug 70 can be fixed to the central pin hole 62 by, for example, one of the following methods; threaded coupling thereto, glued thereto or flanged thereto, or a combination thereof. The peripheral cover surface 68 may be formed as a bolt head 72 in order to make possible the fastening and threaded engagement of the central pin 54 in a machine spindle (not shown in the figures). The rear cover surface 66 comprises one of each pin turned back 74.

A front part of the central grooved part 58 is provided with a plurality of pin cooling outlets 76 that are in fluid communication with the center pin hole 62 through pin cooling ducts 78. Typically, the cooling ducts of pin 78 are uniformly distributed around the central pin hole 62 in order to provide a suitable refrigerant flow through the center pin hole 62 and into the second hole portion 36 of the central body hole

32

A front end of the central grooved portion 58 is provided with a front pin shoulder 80 having a diameter similar to the second diameter D2 and slightly smaller than it. A rear part of the central grooved part 58 is provided with a rear pin shoulder 82 having a diameter similar to the second diameter D2 and slightly smaller therefrom. The front pin shoulder 80 and the rear pin shoulder 82 make it possible to align the pin axis B with the axis of rotation A and prevent radial or angular displacement of the center pin 54 with respect to the central body hole 32. One end Rear of the rear pin shoulder 82 comprises an axial pin bearing surface 84.

The central grooved portion 58 is provided with a plurality of pin grooves 86 that are axially offset from each other. The pin grooves 86 generally extend in a circumferential direction around the central grooved portion 58. In some embodiments, there are at least as many pin grooves 86

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as rows of cutting inserts, if not the same number. In the embodiment shown, the central grooved portion 58 is provided with three slots, namely, a first slot 88 adjacent to the pin cooling outlets 76, a second pin slot 90 rearward toward the first pin slot 88, and , a third pin groove 92 rearward toward the second pin groove 90 and adjacent to the rear pin shoulder 82.

An elastic reclosable seal 94 in the form of a ring is located in one of the pin grooves 86. In a non-pressed position of the removable seal 94, namely, when mounted within a given pin groove 86 and the central pin 54 is not yet inserted in the central body hole 32, the outer diameter of the reclosable seal 94 is slightly larger than the second diameter D2 of the second hole portion 36. The cross section of the resealable seal 94 may be round, quadrilateral, in any other suitable way.

When the cutting tool 10 is mounted on a spindle of a machine, an protruding part of the spindle (not shown) enters the rear hole portion 40 of the tool body 12. Next, the central pin 54 is inserted through the front body face 14, rotated by the screw head 72, and threaded into the spindle.

In this position, the axial support surface 84 rests firmly against the axial hole support surface 52, in this way, the central pin 54 is firmly held in a desired position. In addition, refrigerant leakage through a rear part of the second hole part 36 can be prevented, regardless of the presence of the removable seal 94. In the first hole part 34, the pin face facing back 74 is it can be placed next to the orifice face turned forward 42, thereby forming a very small gap between them and minimizing any refrigerant leakage through the front body face 14. However, in the case that If it is desired to completely avoid any leakage of refrigerant through the first hole part, an auxiliary seal 96 with a ring shape can be inserted into the secondary seal slot 44. In this case, the pin face turned back 74 presses against auxiliary seal 96, and coolant leakage between the pin face turned back 74 and the hole face turned forward 42 is prevented.

The method of adjusting the cooling mechanism of the extended channel milling cutter 10 will be described below. In the embodiment of the milling cutter 10 shown in the figures, it is provided with five channels 20. In the specific application shown in the figures, each channel 20 comprises three cutting inserts 24 that are axially offset with respect to each other to form a peripheral effective cutting edge 28. For clarity, the cutting inserts 24 that are mounted next to the front body face 14 will be referred to as a first row 98 of cutting inserts. The cutting inserts 24 that are axially mounted rearward with respect to the first row 98 will be referred to as a second row 100 of cutting inserts. The cutting inserts 24 that are mounted axially rearward with respect to the second row 100 will be referred to as a third row 102 of cutting inserts.

The cutting tool 10 can be used to cut a relatively narrow shoulder only with the first row 98 of the cutting inserts being active. In such a case, a first depth H1 can be cut by the first row 98. For a deeper depth of cut, the second row 100 of cutting inserts can be used as well as to cut a second depth H2. To cut the deepest possible cut by cutting tool 10, the third row 102 of cutting inserts can also be used and a third depth H3 can be cut.

When only the first end 98 of cutting inserts is used, it may be desirable to supply refrigerant only to the first row 98. In such a case, the resealable seal 94 is placed in the first pin groove 88 as shown in Fig. 5 In this position, the resealable seal 94 is positively pressed between the first pin groove 88 and the central orifice part wall 46, thereby preventing the passage of any refrigerant through it. In this way, the flow of refrigerant will pass through the central pin hole 62 and through the cooling ducts 78 to the second hole part 36. By eliminating any other refrigerant passage, it will be forced into the internal refrigerant holes 48 of the first row 98 will flow through the cooling ducts 50 of the cutting inserts of the first row 98, and will emerge through the cooling holes 30 corresponding to the first row 98 of cutting inserts. In this way, the cooling flow is effectively guided only to the cutting inserts and the unnecessary cooling of the inactive cutting inserts is successfully avoided, which leads to a saving of cooling fluid and, consequently, to reduce Production costs

When only the first row 98 and the second row 100 of the cutting inserts are to be used, changing the cooling mechanism of the cutting tool 10 becomes very easy and practical. The central pin 54 is unscrewed from the spindle and removed from the central body hole 32. In the next stage, the replaceable seal 94 is moved from the first pin slot 88 to the second pin slot 90 and the center pin 54 is reassembled in the tool body 12 in the same manner as described above. This position is killed in Fig. 6. Now, similar to that explained with respect to Fig. 5, the refrigerant is forced to flow only to the first row 98 and the second row 100 of cutting inserts, and it successfully avoids unnecessary cooling of the third row 102.

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When all rows of the cutting inserts are to be used, the replaceable seal 94 moves to the third pin groove 92 to the position shown in Fig. 7, in the same manner as explained above.

In accordance with the foregoing explanation, a person skilled in the art will understand that the present invention 5 provides an efficient and simple method for adjusting the cooling mechanism of an extended channel mill, the disadvantages of the prior art methods being overcome.

Although the present invention has been described with some degree of particularity it is to be understood that different variations and modifications can be made without departing from the philosophy or field of the invention as claimed herein.

10 For example, the central body hole 32 does not have to be provided with a front hole part 34 that is wider than the central hole part and other shapes can be used for the central body hole 32.

The center pin hole 62 does not have to extend to the rear end of the center pin 54. In which case, the cooling means can be supplied to the center pin hole 62 through a radially directed connection instead of being axially connected through of the rear end of the center pin 54.

15 The central pin hole 62 does not have to extend along the entire length of the central pin 54 and can extend only along a part of the central pin 54. In which case, when the central pin hole 62 is Produced as a blind hole without opening to the front cover surface 64, it can be avoided by using a plug 70.

The cooling ducts 50 do not have to extend straight from an internal cooling hole

20 48 to its corresponding cooling hole 30. Thus, for example, the cooling ducts 50 can be formed from two separate segments, directed in different directions, converging together, when a first segment extends from a hole of cooling 30 inside the tool body 10, and, a second segment extends from an internal refrigerant hole 48 to the inside of the tool body 10 and converges with the first segment.

25 The cutting tool 10 shown in the drawings and explained in detail is not limited to cutting a shoulder and other milling operations, for example, side milling, slot milling, etc., may also be applicable.

Claims (9)

5 10 fifteen twenty 25 30 35 40 1. A cutting tool (10) comprising a cutting body (12) having a central body hole (32), a central pin (54) seated within the central body hole (32); wherein: the tool body (12) comprises: a front body face (14); a rear body face (16), opposite to the front body hull (14); one each peripheral body rear (18), which extends backwards from the front body face (14); and at least one channel (20) formed in the peripheral body face (18) and extending backwards from the front body face (14), the at least one channel comprising a first row of insert pockets adjacent to the front body face (14) and at least a second row of insert pockets axially displaced backwards with respect to the first thin one, where each of the insert pockets (22) is associated with a cooling hole (30) which is in fluid communication with the central body hole (32); Y a cutting insert (24) retained within each of the insert pockets (22), the cutting inserts being (24) retained in the first row of insert pockets forming a first row (98) of cutting inserts, and the cutting inserts (24) being retained in the second row of insert pockets formed a second row (100) of cutting inserts; characterized by a removable seal (94) is seated in the central pin (54), where when the removable seal (94) is seated in a first sealing position along the central pin (54), the central body hole (32) is in fluid communication with a first number of rows of cutting inserts; Y when the replaceable seal (94) is seated in a second sealing position along the central pin (54), the central body hole (32) is in fluid communication with a second number of rows of cutting inserts which is different from the first number of rows of cutting inserts. 2. The cutting tool (10) according to claim 1, wherein: the central pin (54) has a pin axis (B) and comprises a central pin hole (62) extending longitudinally along the pin axis (B); and the resealable seal (94) is delimited between the central pin (54) and the central body hole (32); wherein: the central body hole (32) extends in a front-to-back direction of the tool body (12); The central pin (54) has a central grooved part (58) comprising at least two pin grooves (86) axially spaced apart from each other, and the reclosable seal (94) is adjustable between: the first seal position in which the resealable seal is seated in a first of said at minus two pin grooves and the central body hole (32) is fluid communication with the holes of cooling (30) associated with the first number of slots of cutting inserts; and the second sealing position in which the replaceable seal is seated in a second of said at least two pin grooves and the central body hole (32) is in fluid communication with the cooling holes (30) associated with the second number of rows of cutting inserts.

3.

The cutting tool (10) according to claim 2, wherein: the resealable seal (94) is an O-shaped ring.

Four.

The cutting tool (10) according to claim 2, wherein: the central pin hole (62) extends backward to a rear end of the central pin (54).

5.

The cutting tool (10) according to claim 2, wherein:

7 the central grooved part (58) of the central pin (54) comprises at least one pin cooling outlet (76) which is in fluid communication with the central pin hole (62). 6. The cutting tool (10) according to claim 2, wherein: a leading end of the central pin hole (62) is plugged with a plug (70). The cutting tool (10) according to claim 2, wherein: a rear part of the central pin (54) comprises a rear threaded part (60).

8.

The cutting tool (10) according to claim 2, wherein: a front part of the central pin (54) comprises a screw head (72).

9.

The cutting tool (10) according to claim 2, wherein:

10 the central pin (54) comprises a pin bearing surface (84) back towards the central grooved part (58). 10. The cutting tool (10) according to claim 2, further comprising an auxiliary seal (96) seated within a sealed groove (44) in a face facing hole facing (42) of the central body hole (32). 15 11. A method for adjusting a cooling mechanism in a cutting tool (10) having a central body hole (32) connected to a plurality of rows of cutting inserts mounted on the cutter, and a central pin seated inside of the central body hole, the central pin (54) seated therein a removable seal (94) whose position along the central pin can be varied, the method comprising the steps of: 20 vary the position of the resealable seal (94) along the central pin (54) from a first seal position to a second seal position, thereby changing the number of rows of cutting inserts that are in communication from fluid with the central body hole (32), characterized in that The method further comprises the step of disassembling the central pin (54) of the milling cutter (10) before varying the position of the removable seal (94). 25 8